1. Field of the Invention
This invention relates to an improved substantially flat layer of reinforced polymeric material and to a method and apparatus for making the same as well as to a product containing such layer of material.
2. Prior Art Statement
It is known in the art to provide a substantially flat layer of material having opposed substantially parallel spaced apart flat surfaces and comprising polymeric material and reinforcing particles in the polymeric material and having at least a part thereof with the long dimensions thereof oriented in a direction to be substantially parallel with those surfaces. For example see the U.S. Pat. No. 3,657,938 of David G. Fisher and the U.S. Pat. No. 4,027,545 of Jack D. White, Jr. Also see the copending patent application Ser. No. 367,520, filed Apr. 12, 1982, now U.S. Pat. No. 4,511,521, of Paul M. Standley which is considered to be prior art to applicants and wherein the flat layer of material initially comprises a liquid layer of the polymeric material and the reinforcing particles wherein the reinforcing particles were randomly disposed in the liquid layer and then had at least a part thereof oriented while the polymeric material was still in the liquid layer thereof, the liquid layer then having been dried to at least a degree thereof that caused the polymeric material thereof to hold the part of the particles in the oriented condition thereof.
It is known to orient magnetic particles in a flat layer of liquid polymeric material with a magnetic field imposed through the layer in a direction transverse to the flat surfaces thereof and while holding the particles in such oriented condition with the field, heat the polymeric material to set the same and thereby permanently hold the particles in their oriented condition whereby a magnetic polymeric layer is made. For example, see the U.S. Pat. No. 3,312,763 of Donald Peccerill et al.
It is also known to utilize an electrostatic field for augmenting the heat drying of liquid bearing material by passing the liquid bearing material through an electrostatic field while the material is being heated by heating means. For example, see the U.S. Pat. No. 4,338,729 of James T. Candor and the U.S. Pat. No. 4,359,826 of Robert R. Rounsley.